Ciphers, codes and other encryption methods have been used throughout history by most civilization in some form or other to prevent non-authorized people from understanding messages. They have increased in sophistication considerably throughout history and are commonly in use today.
These 11 methods range from some of the earliest examples in history to some of the most advanced encryption techniques in history.
The Caesar Shift Cipher:the Roman Army
Its First Appearance: Unknown – Likely 1st Century AD
When It Was Cracked (if applicable): Unknown – Likely between 5th and 9th Century AD
The cipher was named in honor of Julius Caesar who, according to Suetonius, used it to encrypt military and other official messages.
As the majority of Rome’s enemies were illiterate at this time the cipher remained secure for a time. By the 9th Century AD, after the fall of Rome, records exist of methods to crack it using frequency analysis from Al-Kindi.
Scytale: A Simple Cipher Used By The Spartans
Its First Appearance: Ancient Greece – 7th Century BC
Where It Appeared: Classical/Ancient Greece/Sparta
When It Was Cracked (if applicable): Unknown – But known about by Plutarch (50-120AD)
Scytale was an ancient form of encryption commonly in ancient/classical Greece. It is a form of transposition cipher where letters are re-arranged in the messages prior to being deciphered by the recipient.
This method involved the use of a cylinder around which a parchment was wrapped and the message written onto it. The recipient would use a rod of the exact same dimensions to read the message.Given its simplicity, it was easily decipherable by the enemy too.
Steganography: Hiding Messages in Plain Sight
Its First Appearance: Circa 440BC
Where It Appeared: Ancient Greece
When It Was Cracked (if applicable): Unknown
Steganography is a method of hiding messages ‘in plain sight’ by camouflaging it as something else. The earliest recorded use of this form of ‘encryption’ was described by Herodotus in his Histories.
He describes how Histiaeus sent a message to his vassal, Aristagoras, by shaving the head of his most trusted servant, “marking” the message onto his scalp, and then letting the slave’s hair regrow. The slave was then sent to Aristagoras and ordered to once again shave his head.
The Pigpen Cipher:The Masons
Its First Appearance: Unknown – Perhaps before 1531
Where It Appeared: Europe/Freemasons
When It Was Cracked (if applicable): Unknown
The Pigpen cipher, as known as masonic or freemason cipher, is a geometric simple substitution cipher. It uses symbols to encode the letters within a message.
It is encoded and decoded by producing a grid or set of grids to produce the subsequent symbols.
